Dark powder dispersion liquid, dark powder dispersion body and colored layer-attached base material

ABSTRACT

A dark powder dispersion liquid including a dark pigment, composite tungsten oxide particles and a solid medium, wherein a mass ratio of the dark pigment to the composite tungsten oxide particles (mass of dark-colored pigment/mass of composite tungsten oxide fine particles) is 0.01 or more and 5 or less.

BACKGROUND Technical Field

The present disclosure relates to a dark powder dispersion liquid, adark powder dispersion body, and a colored layer-attached base material,which are used for coloring windows, etc., of automobiles and buildings.

Description of Related Art

Generally, privacy is protected and a design is increased by applying alight-shielding film to a window of an automobile and a building toprevent an inside of the vehicle or the building from being seen throughfrom an outside of the vehicle or the building.

Such a light-shielding film is a film in which a colored layer isprovided on a surface of a transparent film base material such as a PETfilm, and the colored layer is a pigment dispersion body in which apigment is dispersed in a solid medium resin. As such a pigment, it isknown to use Cu—Fe—Mn composite oxide pigment, Cu—Cr composite oxidepigment, Cu—Cr—Mn composite oxide pigment, Cu—Cr—Mn—Ni composite oxidepigment, Cu—Cr—Fe composite oxide pigment, Fe—Cr composite oxide pigmentand Co—Cr—Fe composite oxide pigment, titanium black, titanium nitride,titanium oxynitride, dark azo pigment, perylene black pigment, anilineblack pigment, and carbon black.

For example, Patent Document 1 discloses a technique for alight-shielding film in which a haze value is kept low.

PRIOR ART DOCUMENT Patent Document

[Patent Document 1] JP-A-2000-214310

SUMMARY OF THE DISCLOSURE Problem to be Solved by the Disclosure

Generally, in order to improve the design of an automobile and abuilding, a light-shielding film is required to have a deep black colorwith a low chroma. However, a dark powder dispersion body in which adark pigment is dispersed in a solid medium such as a resin, has a highchroma due to the color of the dark pigment, and a deep black color witha low chroma cannot be obtained in some cases.

Further, depending on an intended use of the light-shielding film, thereare cases where humidity and heat resistance is required.

In view of the above circumstances, the above disclosure is provided,and an object of the present disclosure is to provide a dark powderdispersion body exhibiting a deep black color with low chroma, a coloredlayer-attached base material, and a dark powder dispersion liquid forforming them, and further provide a dark powder dispersion body withexcellent humidity and heat resistance, a colored layer-attached basematerial, and a dark powder dispersion liquid for forming them.

Means for Solving the Problem

That is, in order to solve the above problem, a first invention providesa dark powder dispersion liquid, including

-   -   a dark pigment;    -   composite tungsten oxide particles;    -   and a solvent,    -   wherein a mass ratio of the dark pigment to the composite        tungsten oxide particles (mass of dark pigment/mass of composite        tungsten oxide fine particles) is 0.01 or more and 5 or less.

Advantage of the Disclosure

According to the present disclosure, a dark powder dispersion bodyexhibiting a deep black color with low chroma and a coloredlayer-attached base material, can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing an evaluation result of humidity and heatresistance, in which a colored layer-attached base material according toexamples 8 and 10 to 12, is used.

DETAILED DESCRIPTION OF THE DISCLOSURE

The present invention provides a dark powder dispersion liquid includinga dark pigment, composite tungsten oxide particles, and a solvent,wherein a mass ratio of the dark pigment to the composite tungsten oxideparticles (mass of dark pigment/mass of the composite tungsten oxidefine particles) is 0.01 or more and 5 or less, and the dark powderdispersion liquid is used to produce a dark powder dispersion body and acolored base material.

Hereinafter, the present invention will be described in an order of (1)a dark pigment, (2) composite tungsten oxide fine particles, (3) a darkpowder dispersion liquid, (4) a dark powder dispersion body, and (5) acolored layer-attached base material.

(1) Dark Pigment

A dark pigment is a pigment that colors a dark powder dispersion body ina colored layer of a light-shielding film and lowers a visible lighttransmittance.

However, the dark pigment may have a yellowish or greenish tint.Therefore, it may be difficult to achieve deep blackness with low chromaonly by using these dark pigments.

In the present invention, chroma means chroma c* in a L*, a*, b* colorsystem based on JIS Z 8701 1999 and JIS Z 8781-4 2013. The chroma c* isexpressed by the following formula (1).

Chroma c*=(a* ² +b* ²)^(1/2)   Formula 1

Here, the present inventors came up with an idea of using a mixture of adark pigment (black pigment) selected from Cu—Fe—Mn composite oxidepigment, Cu—Cr composite oxide pigment, Cu—Cr—Mn composite oxidepigment, Cu—Cr—Mn—Ni composite oxide pigment, Cu—Cr—Fe composite oxidepigment, Fe—Cr composite oxide pigment, Co—Cr—Fe composite oxidepigment, titanium black, titanium nitride, titanium oxynitride, dark azopigment, perylene black pigment, aniline black pigment, carbon black,and composite tungsten oxide fine particles which will be describedlater.

That is, the deep black color with low chroma is realized bysupplementing yellowish and greenish tint of the dark pigment withbluish tint of the composite tungsten oxide fine particles.

Among these dark pigments, Cu—Fe—Mn composite oxide pigment, Cu—Crcomposite oxide pigment, Cu—Cr—Mn composite oxide pigment, Cu—Cr—Mn—Nicomposite oxide pigment, Cu—Cr—Fe composite oxide pigment, Fe—Crcomposite oxide pigment and Co—Cr—Fe composite oxide pigment are knownto be composite oxides having a spinel structure. Then, a compound suchas Cu, Fe, and Mn is used as a raw material, and is synthesized byfiring at a temperature of 500° C. or higher.

As for the color of the pigment, for example, when a material thatshields light in a short wavelength region is used, the short wavelengthregion of visible light (blue) is also slightly shielded, and the darkpowder dispersion body has a yellowish tint. On the other hand, when amaterial that shields light in a long wavelength region is used, thelong wavelength region of visible light (red) is also slightly shielded,and the dark powder dispersion body has a bluish tint. Then, when amaterial that shields light in both the short and long wavelengthregions is used, the dark powder dispersion body will be greenish.Therefore, it is found that by combining the dark pigment and thecomposite tungsten oxide fine particles, a deep black color with lowchroma can be expressed in the dark color powder dispersion body of thepresent invention.

Then preferably, since the composite tungsten oxide fine particlesabsorb and shield near-infrared ray more than visible light, when thedark powder dispersion body of the present invention is used for alight-shielding film, it is possible to obtain an effect of absorbingand shielding near-infrared rays contained in sunlight, preventing themfrom entering the room, and suppressing an increase in room temperature.

An average dispersed particle size of the dark pigment is preferably 200nm or less, more preferably 1 nm or more and 100 nm or less. This isbecause when the average dispersed particle size of the dark pigmentexceeds 200 nm, a haze of the dark powder dispersion body may increase.The average dispersed particle size of the dark pigment can be measuredusing an ELS-8000 manufactured by Otsuka Electronics Co., Ltd. based ona dynamic light scattering method.

(2) Composite Tungsten Oxide Fine Particles

Regarding the composite tungsten oxide fine particles used in thepresent invention, (a) property of the composite tungsten oxide fineparticles and (b) a method for producing the composite tungsten oxidefine particles, will be described in this order.

(a) Property of the Composite Tungsten Oxide Fine Particles

When the composite tungsten oxide fine particles have a compositionrepresented by a general formula MxWyOz (wherein M is H, He, alkalimetals, alkaline earth metals, rare earth elements, one or more elementsselected from Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Zn,Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb,V, Mo, Ta, Re, Be, Hf, Os, Bi, I, and Yb, and W is tungsten, O isoxygen, satisfying 0.001≤x/y≤1, 2.0<z/y≤3.0), the composite tungstenoxide fine particles exhibit near-infrared absorbing properties andbecome near-infrared absorbing fine particles, which is a preferablecomposition.

The composite tungsten oxide fine particles represented by the generalformula MxWyOz will be further described. The values of the M element,x, y, and z in the general formula MxWyOz and the crystal structurethereof are closely related to a free electron density of thenear-infrared absorbing fine particles, and greatly affect thenear-infrared absorbing properties.

In general, the near-infrared absorption properties are low becauseeffective free electrons do not exist in tungsten trioxide (WO₃).

It is found by the present inventors that by adding element M (whereinthe element M is one or more kinds selected from H, He, alkali metals,alkaline earth metals, rare earth elements, Mg, Zr, Cr, Mn, Fe, Ru, Co,Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb,Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, I,and Yb) to the tungsten oxide to produce a composite tungsten oxide,free electrons are generated in the composite tungsten oxide, absorptionproperties derived from the free electrons appear in a near-infraredregion, and it becomes effective as a near-infrared absorbing materialwith a wavelength of around 1000 nm, and the composite tungsten oxide ismaintained in a chemically stable state and is effective as anear-infrared absorbing material with excellent weather resistance.Further, the element M is preferably Cs, Rb, K, Tl, Ba, Cu, Al, Mn, orIn. Especially, when the element M is Cs or Rb, the composite tungstenoxide tends to have a hexagonal crystal structure, and exhibits theproperty of transmitting visible light and absorbing and shieldingnear-infrared rays.

Here, finding of the present inventors regarding a value of x whichindicates an amount of the added element M, will be described.

When the value of x/y is 0.001 or more, a sufficient amount of freeelectrons are generated and a desired near-infrared absorption propertycan be obtained. Then, as the amount of the added element M increases,an amount of supplied free electrons increases and the near-infraredabsorption properties also improve. However, the effect saturates whenthe value of x/y is about 1. Further, when the value of x/y is 1 orless, it is possible to avoid a formation of an impurity phase in thecomposite tungsten fine particles, which is preferable.

Next, the finding of the present inventors regarding a value of zindicating a control of an oxygen amount will be described.

In the composite tungsten fine particles represented by the generalformula MxWyOz, the value of z/y is preferably 2.0<z/y ≤3.0, morepreferably 2.2≤z/y≤3.0, still more preferably 2.6≤z/y≤3.0, mostpreferably 2.7≤z/y≤3.0. When this z/y value exceeds 2.0, it is possibleto avoid an appearance of a crystal phase of WO₂, which is a compoundother than an intended compound, in the composite tungsten oxide, andchemical stability as a material can be obtained, and therefore theabove composite tungsten fine particles can be used as an effectivenear-infrared absorbing material. On the other hand, when the value ofz/y is 3.0 or less, a required amount of free electrons is generated inthe tungsten oxide, and the above composite tungsten fine particles canbe used as an efficient near-infrared absorbing material.

The composite tungsten oxide fine particles have a structure oftetragonal or cubic tungsten bronze in addition to the hexagonalstructure, but are effective as a near-infrared absorbing materialregardless of which structure they have. However, an absorption positionin the near-infrared region tends to change depending on the crystalstructure of the composite tungsten oxide fine particles. That is, theabsorption position in the near-infrared region tends to move to alonger wavelength side in the tetragonal crystal than in the cubiccrystal, and to move further to the longer wavelength side in thehexagonal crystal than in the tetragonal crystal. Further, accompanyingthe change in the absorption position, the hexagonal crystal has alowest absorption in a visible light region, followed by the tetragonalcrystal, and the cubic crystal has a highest absorption among them.

Based on the above finding, it is preferable to use the hexagonaltungsten bronze for the purpose of transmitting more lights in thevisible light region and shielding more lights in the near-infraredregion. When the composite tungsten oxide fine particles have ahexagonal crystal structure, the fine particles have improvedtransmission in the visible light region and improved absorption in thenear-infrared region.

When the composite tungsten oxide fine particles having a hexagonalcrystal structure have a uniform crystal structure, the amount of theadded element M is preferably 0.2 or more and 0.5 or less, morepreferably 0.29≤x/y≤0.39 in terms of the value of x/y. Theoretically,when z/y=3, the value of x/y is 0.33. Then, it is considered that theadded element M is arranged in all hexagonal voids.

An average dispersed particle size of the composite tungsten oxide fineparticles is preferably 800 nm or less and 1 nm or more, more preferably200 nm or less and 1 nm or more. The fact that the composite tungstenoxide fine particles preferably have an average dispersed particle sizeof 200 nm or less is the same for the composite tungsten oxide fineparticles in the dark powder dispersion liquid. This is because haze canbe kept low when the average dispersed particle size is 200 nm or less.The average dispersed particle size is preferably 1 nm or more, morepreferably 10 nm or more. The average dispersed particle size can bemeasured using an ELS-8000 manufactured by Otsuka. Electronics Co., Ltd.based on a dynamic light scattering method.

Then, in the composite tungsten oxide fine particle dispersion body inwhich these composite tungsten oxide fine particles are individuallydispersed in a solid medium such as a resin, a* and b* show negativevalues in a L*, a*, b* color system, and the composite tungsten oxidefine particle dispersion body has a bluish tint. The bluish coloring isnot so strong in a region where the visible light transmittance exceeds70%, but is strong in a region where the visible light transmittance isas low as 5 to 70%. Further, when the visible light transmittance isextremely low, such as less than 1%, a film has a black tint, and thebluish tint becomes inconspicuous, but high chroma and deep black cannotbe realized.

(b) Method for Producing Composite Tungsten Oxide Fine Particles

The composite tungsten oxide fine particles represented by the generalformula MxWyOz can be obtained by heat-treating a tungsten compoundstarting material in an inert gas atmosphere or a reducing gasatmosphere.

First, the tungsten compound starting material will be described.

The tungsten compound starting material is preferably one or moreselected from tungsten trioxide powder, tungsten dioxide powder, ortungsten oxide hydrate, or tungsten hexachloride powder, or ammoniumtungstate powder, or tungsten oxide hydrate powder obtained bydissolving tungsten hexachloride in alcohol and then drying it, ortungsten oxide hydrate powder obtained by dissolving tungstenhexachloride in alcohol, adding water to cause precipitation, and dryingthe precipitate, or tungsten compound powder obtained by drying anammonium tungstate aqueous solution, and metallic tungsten powder.

When producing the composite tungsten oxide fine particles, it is morepreferable to use an ammonium tungstate aqueous solution or a tungstenhexachloride solution from a viewpoint that each element whose startingmaterial is a solution can be uniformly mixed easily. Composite tungstenoxide fine particles can be obtained by heat-treating these rawmaterials in an inert gas atmosphere or a reducing gas atmosphere.Further, a tungsten compound containing the element M in the form of asingle element or a compound, is used as a starting material.

Here, in order to produce a starting material in which each component ishomogeneously mixed at a molecular evel, it is preferable to mix eachraw material in a solution, and it is preferable to use the tungstencompound starting raw material that contains the element M and issoluble in a solvent such as water or an organic solvent. For example,preferable examples include, but are not limited to, tungstates,chloride salts, nitrates, sulfates, oxalates, oxides, carbonates,hydroxides, etc., containing the element M, as long as a solution isformed thereby.

Next, heat treatment in the inert gas atmosphere or the reducing gasatmosphere will be described.

First, a heat treatment condition in the inert gas atmosphere ispreferably 650° C. or higher. A starting material heat-treated at 650°C. or higher has a sufficient near-infrared absorbing power and isefficient as heat ray shielding fine particles. As the inert gas, aninert gas such as Ar or N₂ is preferably used.

Further, a heat treatment condition in the reducing atmosphere is asfollows: it is preferable to first heat-treat the starting material at atemperature of 100° C. to 650° C. in the reducing gas atmosphere, andthen heat-treat it at a temperature of 650° C. to 1200° C. in the inertgas atmosphere. The reducing gas at this time is not particularlylimited, but H₂ is preferable. Then, when H₂ is used as the reducinggas, the composition of the reducing atmosphere is preferably, forexample, an inert gas such as Ar or N₂ mixed with H₂ at a volume ratioof 0.1% or more, and more preferably, it is mixed at 0.2% or more. Whenthe H₂ content is 0.1% or more at a volume ratio, reduction can proceedefficiently.

Hydrogen-reduced starting material powder contains a Magneli phase andexhibits good heat ray shielding property. Accordingly, even in thisstate, the particles can be used as heat ray shielding fine particles.

The surface of the composite tungsten oxide fine particles according tothe present invention is preferably coated with a compound, preferablyan oxide, containing one or more of Si, Ti, Zr and Al, from a viewpointof improving weather resistance. In order to perform a surfacetreatment, a known surface treatment may be performed using a compoundwhich is an organic compound containing one or more of Si, Ti Zr and Al.For example, the composite tungsten oxide fine particles and anorganosilicon compound may be mixed and hydrolyzed.

(3) Dark Powder Dispersion Liquid

The dark powder dispersion liquid according to the present invention isobtained by mixing and dispersing the above-described dark pigment andcomposite tungsten oxide in an appropriate solvent.

Hereinafter, explanation will be given for the dark powder dispersionliquid according to the present invention, in an order of (a) mixingratio of the dark pigment and the composite tungsten oxide fineparticles, (b) solvent, (c) dispersant, (d) a method for producing thedark powder dispersion liquid, and (e) other additive.

(a) Mixing Ratio of the Dark Pigment and the Composite Tungsten OxideFine Particles

The mixing ratio of the dark pigment and the composite tungsten oxidefine particles (mass of the dark pigment/mass of the composite tungstenoxide fine particles) contained in the dark powder dispersion liquidaccording to the present embodiment is 0.01 or more and 5 or less,preferably 0.05 or more and 1 or less, more preferably 0.1 or more. 0.2or less.

That is, by combining the dark pigment and the composite tungsten oxidefine particles at a predetermined ratio, a deep black color with lowchroma is realized by supplementing yellowish and greenish tints of thedark pigment with a blue tint of the composite tungsten oxide fineparticles.

As for the color of the pigment, when a material that shieldsultraviolet light is used, the short wavelength region (blue) of thevisible light is also slightly shielded, and the dark powder dispersionbody has a yellowish tint. On the other hand, when a material thatshields near-infrared rays is used, the long-wavelength region of thevisible light (red) is also slightly shielded, resulting in a bluishtint. Then, when a material that shields both ultraviolet rays andnear-infrared rays is used, it has a greenish tint. Therefore, it isfound that by combining the dark pigment and the composite tungstenoxide fine particles, a deep black color with low chroma can beexpressed in the dark color powder dispersion body of the presentembodiment.

Then, since the composite tungsten oxide fine particles absorb andshield near-infrared rays more than visible lights, when the dark powderdispersion body according to the present embodiment is used as alight-shielding film or as a colored layer-attached base material, it ispossible to absorb and shield near-infrared rays contained in sunlight,prevent them from entering indoors and automobiles, and suppresstemperature rise.

(b) Solvent

The solvent used in the dark powder dispersion liquid according to thepresent invention is not particularly limited, and may be appropriatelyselected according to a binder when containing an inorganic binder or aresin binder, under a coating/kneading condition, in a coating/kneadingenvironment. For example, various organic solvents such as water,alcohols such as ethanol, propanol, butanol, isopropyl alcohol, isobutylalcohol, diacetone alcohol, ethers such as methyl ether, ethyl ether,propyl ether, esters, ketones such as acetone, methyl ethyl ketone,diethyl ketone, cyclohexanone, isobutyl ketone, aromatic hydrocarbonssuch as toluene, can be used.

Further, a resin monomer or oligomer may be used as the solvent.Further, a liquid resin in which a styrene resin, etc., is dissolved intoluene, or a liquid plasticizer for plastics may be used.

Further, a mixture of the solvents described above may also be used.

The solvent is preferably contained in the dark powder dispersion liquidof the present embodiment, in an amount of 50 parts by mass or more and2000 parts by mass or less, more preferably 200 parts by mass or more,with respect to a total of 100 parts by mass of the dark pigment and thecomposite tungsten oxide fine particles.

(c) Dispersant

In order to further improve a dispersion stability of the fine particlesin the dark powder dispersion liquid, it is of course possible to addvarious dispersants, surfactants, coupling agents, etc. Further, whenwater or a water-soluble organic substance is used as the solvent, anacid or an alkali may be added as necessary to adjust pH of thedispersion liquid.

The dispersant is desirably a polymer dispersant having an amino group.It adsorbs on the surface of the dark pigment particles and thecomposite tungsten oxide fine particles described above, preventsaggregation of the composite tungsten oxide fine particles, and iseffective in dispersing these fine particles uniformly in the darkpowder dispersion body. The polymer dispersant having an amino grouppreferably has an amine value of 5 to 100 mgKOH/g and a molecular weightMw of 2,000 to 200,000.

The amino group polymer dispersant according to the present embodimentis a compound having a basic group such as an amino group in a moleculeof the dispersant. An example of such a compound having the basic groupsuch as an amino group in the molecule of the dispersant includespolyolefin resin, polyester resin, acrylic resin, polyurethane resin,and amide resin in a main chain. A compound having an acrylic resin in amain chain is more preferable.

Further, examples of the preferable commercially available polymerdispersants having such amino groups include: amino group polymerdispersants manufactured by BYK-Chernie Japan, such as Disperbyk-112,Disperbyk-116, Disperbyk-130, Disperbyk-161, Disperbyk-162,Disperbyk-164, Disperbyk-166, Disperbyk-167, Disperbyk-168,Disperbyk-2001, Disperbyk-2020, Disperbyk-2050, Disperbyk-2070, andDisperbyk-2150, amino group polymer dispersants manufactured byAjinomoto Fine-Techno Co., Inc. such as Ajisper PB821, Ajisper PB822,Ajisper PB711, amino group polymer dispersants manufactured by KusumotoKasei Co., Ltd., such as Disparlon 1860, Disparlon DA703-50, DisparlonDA7400, and amino group polymer dispersants manufactured by BASF JapanCo., Ltd., such as EFKA-4400, EFKA-4401, EFKA-5044, EFKA-5207,EFKA-6225, EFKA-4330, EFKA-4047, EFKA-4060.

Further, a dispersant having a hydroxyl group and/or a carboxyl groupmay be used in combination with the amino group polymer dispersant, or apolymer dispersant with an amino group may have a hydroxyl group and/ora carboxyl group. Any of such polymer dispersants adsorbs on the surfaceof the composite tungsten oxide fine particles described above, preventsaggregation of the composite tungsten oxide fine particles and exhibitsthe effect of uniformly dispersing these fine particles in the darkpowder dispersion body.

The polymer dispersant having a hydroxyl group preferably has an OHvalue of 10 to 200 mgKOH/g and a molecular weight Mw of 1,000 to150,000.

Examples of the polymer dispersant having the hydroxyl group accordingto the present embodiment include an acrylic resin having a hydroxylgroup (sometimes called acrylic polyol), an acrylic/styrene copolymerhaving a hydroxyl group, etc.

An example of the polymer dispersant having the hydroxyl group includesacrylic polyol and a commercially available product such as UH seriesmanufactured by Toagosei Co., Ltd.

The polymer dispersant having the carboxyl group preferably has an acidvalue of 0.1 to 100 mgKOH/g and a molecular weight Mw of 2,000 to200,000.

Examples of the polymer dispersant having the carboxyl group accordingto the present embodiment include an acrylic resin and anacrylic-styrene copolymer, etc., having the carboxyl group.

Examples of the polymer dispersant having the carboxyl group includecommercially available acrylic resin having an acid value of 1 or more,UC series and UF series manufactured by Toagosei Co., Ltd., etc.

In the dark powder dispersion liquid according to the present invention,a total content of these polymer dispersants is preferably 20 parts bymass or more and 200 parts by mass or less as the solid content of thedispersant with respect to a total of 100 parts by mass of the darkpigment and the composite tungsten oxide fine particles. This is becausewhen the content of the polymer dispersant is within this range, thedark pigment and the composite tungsten oxide fine particles areuniformly dispersed in the dark powder dispersion body, and a low hazecan be achieved. Specifically, by containing 20 parts by mass or more ofthe amino group polymer dispersant with respect to a total of 100 partsby mass of the dark pigment and the composite tungsten oxide fineparticles, the haze value of the dark powder dispersion body can bereduced, and by containing 200 parts by mass or less, a mechanicalstrength of the dark powder dispersion body can be ensured.

(d) A Method for Producing the Dark Powder Dispersion Liquid

A dispersion method for producing the dark powder dispersion liquid maybe a method for uniformly dispersing the dark pigment and the compositetungsten oxide fine particles in the dispersion liquid, and for example,a bead mill, a ball mill, a sand mill, a paint shaker, an ultrasonichomogenizer, etc., can be used.

Further, in order to obtain the dark powder dispersion liquid, a pigmentdispersion liquid containing a dark pigment, a solvent and a polymerdispersant optionally added, and a composite tungsten oxide dispersionliquid containing composite tungsten oxide fine particles, a solvent,and a polymer dispersant optionally added, are prepared by thedispersion method described above, so that each of them may be mixed ina predetermined value of the mixing ratio of the dark pigment and thecomposite tungsten oxide fine particles.

(e) Other Additive

When humidity and heat resistance is required in “(4) dark powderdispersion body” or “(5) colored layer-attached base material” describedlater, it is also preferable to add an additive to the dark powderdispersion liquid used for producing them, to improve the humidity andheat resistance.

In view of the fact that the dark powder dispersion body and the coloredlayer-attached base material according to the present invention may beused in a situation where humidity and heat resistance is required, theinventors of the present invention conducted research on the cause of adeterioration of the near-infrared shielding properties of the darkpowder dispersion body and the colored layer-attached base material overtime due to humidity and heat. Then, it is found that humidity intrudingfrom the air, metal ions derived from dark powder, or ultraviolet raysfrom the outside act catalytically on a solid medium and a transparentfilm base material, causing decomposition and deterioration. It isestimated that a decomposition product (radical) generated during thedecomposition and deterioration desorb the element M in the compositetungsten oxide fine particles, and therefore the near-infrared shieldingproperty deteriorates over time.

Based on the above estimation, by adding a metal deactivator or a metalsalt as an additive to the dark powder dispersion liquid, the inventorshave come up with the following configuration. Due to addition of themetal deactivator or the metal salt as an additive to the dark powderdispersion liquid, the metal deactivator or the metal salt is present inthe dark powder dispersion body or the colored layer-attached basematerial. With this configuration, the metal deactivator and the metalsalt are present in the vicinity of and/or on the surface of theinfrared shielding material fine particles. Then, an action of the metaldeactivator and the metal salt sufficiently traps humidity that entersfrom the air. Further, metal ions derived from the dark powder andradicals generated by ultraviolet rays are captured by the action ofthis metal deactivator and metal salt, and chain generation of harmfulradicals is suppressed. As a result, it is found that deterioration ofthe infrared shielding property over time can be suppressed.

There are many unknown points about the action of these metaldeactivator and metal salt, and it is conceivable that actions otherthan those described above works. Therefore, the actions are not limitedto the above actions.

Preferably, specific examples of the metal deactivator include:salicylic acid derivatives N-(2H-1,2,4-triazol-5-yl) salicylamide,N,N-bis(6,5-di-t-butylsalicyloyl)hydrazine, N,N-bis(6-t-butylmethylsalicyloyl) hydrazine, etc., hydrazine derivativedodecanedioic acid bis[N2-(2-hydroxybenzoyl)hydrazide],3-(3,5-di-tert-butyl-4-hydroxyphenyl)-N′-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoyl]propanehydrazide,etc., oxalic acid derivativesN,N′-bis[2-[2-(3,5-di-tert-butyl-4-hydroxyphenyl)ethylcarbonyloxy]ethyl]oxamide,N′-benzylidene hydrazide, oxalyl-bis (benzylidene hydrazide) etc.

Further, specific examples of the metal salt include: magnesium lactate,aluminum lactate, calcium lactate, etc., and carbonates such as calciumcarbonate, magnesium carbonate (magnesium carbonate hydroxide),strontium carbonate, etc.

Further, an amount of the metal deactivator or the metal salt to beadded (however, in the present invention, when the metal deactivator orthe metal salt contains water of crystallization or water of hydration,the mass of the metal deactivator and the metal salt itself excludingthe mass of the water of crystallization and water of hydration isdefined as an added amount.) is preferably twice or more or 10 times orless when expressed as a mass ratio of the dark pigment. This is becausean effect of the metal deactivator or the metal salt can be obtained byadding twice or more when expressed as the mass ratio of the darkpigment, and on the other hand, by adding 10 times or less of the darkpigment in mass ratio, it is possible to avoid the inability to maintainthe transparency of the film due to light scattering caused by the metaldeactivator or the metal salt.

It is preferable to add various metal deactivators and metal salts tothe dark powder dispersion liquid after preparing the dark powderdispersion liquid. Then, when the metal deactivator or the metal salt ispowder, in order to suppress an occurrence of light scattering in thedark powder dispersion body or in the colored layer-attached basematerial, it is preferable to reduce a particle size. Specifically, aparticle size of 5 nm to 100 nm is desirable. When a thickness is 100 nmor less, the light scattering can be suppressed, and transparency of thefilm can be ensured. When the particle size is 5 nm or more, it ispossible to avoid excessive pulverization of the metal deactivator andthe metal salt, which is preferable from a viewpoint of productivity.

From the above viewpoint, when the metal deactivator or the metal saltis powdery, it is preferable to mix the powdered metal deactivator ormetal salt with an appropriate solvent and perform pulverization toprepare a pulverization liquid.

The solvent is not particularly limited, and may be appropriatelyselected according to a dark powder dispersion system, the dark powderdispersion body, and the colored layer-attached base material. Forexample, it is possible to use water, various organic solvents such asalcohols such as ethanol, propanol, butanol, isopropyl alcohol, isobutylalcohol, diacetone alcohol, ethers such as methyl ether, ethyl ether,propyl ether, esters, ketones such as acetone, methyl ethyl ketone,diethyl ketone, cyclohexanone, isobutyl ketone, methyl isobutyl ketone,and aromatic hydrocarbons such as toluene. Further, a resin monomer oroligomer may be used as the solvent. Further, a liquid resin in which astyrene resin, etc., is dissolved in toluene, or a liquid plasticizerfor plastics may be used.

Further, the mixture of the solvents described above may also be used.

As the above-described pulverization method, a general pulverizationmethod can be used, and a bead mill, a ball mill, a sand mill, a paintshaker, an ultrasonic homogenizer, etc., can be used.

When adding the prepared pulverization liquid to the dark powderdispersion liquid, for example, it is preferable to uniformly dispersethe pulverization liquid into the dark powder dispersion liquid byperforming ultrasonic treatment for 5 to 10 minutes.

(4) Dark Powder Dispersion Body

The dark powder dispersion body according to the present invention isobtained by dispersing the above-described dark pigment and compositetungsten oxide fine particles in a suitable solid medium.

Specifically, a resin constituting a solid medium is added to a darkpowder dispersion liquid to obtain a dispersion liquid (coating liquid)for forming a dark powder dispersion body. Then, by coating a surface ofan appropriate base material with the dispersion liquid for forming adark powder dispersion body, then, removing the solvent by apredetermined method such as evaporation, and curing the resin, acolored layer-attached base material is obtained in which the darkpowder dispersion body is provided as a colored layer on the surface ofthe base material.

A dispersion state and a mixing ratio of the dark pigment and thecomposite tungsten oxide fine particles in the dark powder dispersionliquid are maintained in the dark powder dispersion body obtained fromthe dark powder dispersion liquid according to the present. As a result,according to the dark powder dispersion body of the present invention,10 or less of chroma c* and 50% or less of a near-infrared transmittancecan be achieved, when a dispersion liquid (coating liquid) for forming adark powder dispersion body is formed by diluting a masterhatchdescribed later with a solid medium resin so that a visible lighttransmittance is 5 to 70%, the chroma c* is preferably 5 or less, morepreferably 4 or less, and even more preferably 3 or less. By loweringthe chroma c*, a deep black that can be visually confirmed can berealized, and the windows of automobiles and buildings can be made adeep black, thereby improving a design.

Further, when a Cu—Fe—Mn composite oxide pigment and/or a Cu—Crcomposite oxide pigment is selected as a dark pigment, the visible lighttransmittance and the near-infrared transmittance can be desired valueswhile keeping the value of c* below 4.5, by controlling the mixing ratioof the dark pigment, composite tungsten oxide fine particles, resin,etc., in the dark powder dispersion body mixed with the compositetungsten oxide fine particles and a resin which is a medium, etc. As aresult, this is a preferable configuration because it facilitates adevelopment of the dark powder dispersion body having optical propertiesaccording to usage, etc.

Further, a resin monomer that becomes a solid medium when being cured,may be used as a solvent for the dark powder dispersion liquid accordingto the present invention. When the resin monomer is used as a solvent, acoating method is not particularly limited as long as the surface of abase material can be uniformly coated with a near-infrared shieldingmaterial fine particle dispersion body. Examples thereof include barcoating, gravure coating, spray coating, dip coating, etc. Further,according to the dark powder dispersion body in which a dark pigment andcomposite tungsten oxide fine particles are dispersed directly in abinder resin, evaporation of the solvent is not required after coatingthe surface of the base material, which is environmentally andindustrially preferable.

As the solid medium described above, for example, a UV curable resin, athermosetting resin, an electron beam curable resin, a room temperaturecurable resin, a thermoplastic resin, etc., can be selected depending onthe purpose. Specific examples thereof include: polyethylene resin,polyvinyl chloride resin, polyvinylidene chloride resin, polyvinylalcohol resin, polystyrene resin, polypropylene resin, ethylene-vinylacetate copolymer, polyester resin, polyethylene terephthalate resin,fluorine resin, polycarbonate resin, acrylic resin, and polyvinylbutyral resin. These resins may be used singly or in combination.

Further, it is also possible to produce a dark powder dispersion body byvolatilizing a solvent component in the dark powder dispersion liquidcontaining a polymer dispersant, then, producing a darkpigment-containing masterbatch by mixing a dark pigment dispersionpowder containing the dark pigment, the composite tungsten oxide fineparticles, and the polymer dispersant, with a polycarbonate resin, etc.,melted at a temperature higher than a melting temperature, then, meltingand mixing the masterbatch with a polycarbonate resin, etc., melted at atemperature higher than the melting temperature, and forming it into afilm or a board by a known method.

(5) Colored Layer-Attached Base Material

A colored layer-attached base material can be obtained by providing thedark powder dispersion body according to the present invention as acolored layer on the surface of a transparent base material such as atransparent glass base material or a transparent film base material. Aplate glass such as a soda lime glass can be used as the transparentglass base material, and a resin film such as a PET film can be used asthe transparent film base material.

Of course, the dark powder dispersion body may be sandwiched between twoor more transparent base materials to form a colored layer-attached basematerial.

EXAMPLES

The present invention will be described more specifically with referenceto examples.

First, an evaluation method will be described in an order of (1) visiblelight transmittance and near-infrared transmittance, (2) L*, a*, b*color system characteristics and chroma c*, and (3) average dispersedparticle size.

(1) Visible Light Transmittance and Near-Infrared Transmittance

A visible light transmittance and a near-infrared transmittance of asample were measured with a spectrophotometer (UH4150 manufactured byHitachi, Ltd.). Then, the visible light transmittance and thenear-infrared transmittance were measured at a wavelength from 750 nm to1500 nm according to ISO9050.

(2) L*, a*, b* Color System Characteristics and Chroma c*

L*, a*, b* color system characteristics of the samples were measuredwith a spectrophotometer (Hitachi UH4150). Chroma c* was calculated bythe following formula 2.

Chroma c*=(a* ² +b* ²)^(1/2)   Formula 2

The L* a*, b* color system characteristics were measured by thefollowing procedure.

A spectral transmittance (wavelength dependence of transmittance) of thesample is measured.

Based on JIS Z 8701 1999, the measured spectral transmittance isconverted into X₁₀, Y₁₀, and Z₁₀ color values in a 10° field of view ofa D65 light source.

The converted X₁₀, Y₁₀, Z₁₀ tint values are converted to L*, a*, b*based on JIS Z 8781-4 2013.

(3) Average Dispersed Particle Size

An average dispersed particle size was measured using an ELS-8000manufactured by Otsuka Electronics Co., Ltd. based on a dynamic lightscattering method.

Examples 1 to 12, Comparative Examples 1 to 8 (a) Preparation of a DarkPowder Dispersion Liquid

Preparation of a Cu—Fe—Mn composite oxide pigment dispersion liquid willbe described as a dark powder dispersion liquid.

100 parts by mass of Cu—Fe—Mn composite oxide pigment (DainichiseikaDipyroxide TM Black #3550), 800 parts by mass of MIBK as a solvent, 100parts by mass of a dispersant a (a dispersant having an amine-containinggroup and an acrylic backbone, amine value 42 mgKOH/g), were put in acontainer, which were then pulverized in a paint shaker for 20 hoursusing 0.3 mm zirconia beads. Then, a dispersion liquid of a Cu—Fe—Mncomposite oxide pigment having an average dispersed particle size of 100nm was obtained.

As a dark powder dispersion liquid, preparation of a Cu—Cr mixed oxidepigment dispersion liquid will be described.

100 parts by mass of Cu—Cr composite oxide pigment (DainichiseikaDipyroxide Black #9510), 800 parts by mass of MIBK as a solvent, and 100parts by mass of a dispersant a were put in a container, which were thenpulverized in a paint shaker for 20 hours using 0.3 mm zirconia beads.Then, a Cu—Fe—Mn mixed oxide pigment dispersion liquid having an averagedispersed particle size of 150 nm was obtained.

(b) Preparation of Composite Tungsten Oxide Fine Particle DispersionLiquid

Preparation of a Cs_(0.33)WO₃ particle dispersion liquid as a compositetungsten oxide fine particle dispersion liquid will be described.

100 parts by mass of Cs_(0.33)WO₃ particles (manufactured by SumitomoMetal Mining), 300 parts by mass of MIBK as a solvent, and 100 parts bymass of dispersant a are placed in a container, which were thenpulverized in a paint shaper for 20 hours using 0.3 mm zirconia beads.Then, a Cs_(0.33)WO₃ particles dispersion liquid having an averagedispersed particle size of 30 nm was obtained.

(c) Preparation of Dark Powder Dispersion Liquid and a Dispersion Liquid(Coating Liquid) for Forming a Dark Powder Dispersion Body

100 parts by mass of a Cu—Fe—Mn composite oxide pigment dispersionliquid and 100 parts by mass of a Cs_(0.33)WO₃ particle dispersionliquid were mixed to prepare a dark powder dispersion liquid accordingto examples 1 to 3.

20 parts by mass of Cu—Fe—Mn composite oxide pigment dispersion liquidand 100 parts by mass of Cs_(0.33)WO₃ particle dispersion liquid weremixed to prepare a dark powder dispersion liquid according to examples 4to 7.

10 parts by mass of Cu—Fe—Mn composite oxide pigment dispersion liquidand 100 parts by mass of Cs_(0.33)WO₃ particle dispersion liquid weremixed to prepare a dark powder dispersion liquid according to examples 8and 10 to 12.

20 parts by mass of a Cu—Cr composite oxide pigment dispersion liquidand 100 parts by mass of Cs_(0.33)WO₃ particle dispersion liquid weremixed to prepare a dark powder dispersion liquid according to example 9.

Only 100 parts by mass of Cs_(0.33)WO₃ particle dispersion liquid wasused as a dark powder dispersion liquid according to comparativeexamples 1 to 5.

Only 100 parts by mass of Cu—Fe—Mn mixed oxide pigment dispersion liquidwas used as a dark powder dispersion liquid according to comparativeexamples 6 to 8.

Further, in the dark powder dispersion liquid according to example 10,800 parts by mass of magnesium carbonate hydroxide (manufactured byKanto Kagaku) was added to 100 parts by mass of Cs_(0.33)WO₃ particles.

Further, in the dark powder dispersion liquid according to example 11,632 parts by mass of magnesium lactate (manufactured by Kanto Kagaku)was added to 100 parts by mass of Cs_(0.33)WO₃ particles.

Since the magnesium lactate (manufactured by Kanto Kagaku) was atrihydrate, an amount of added magnesium lactate containing hydratedwater was 800 parts by mass.

Further, in the dark powder dispersion liquid according to example 12, asalicylic acid derivative (N-(2H-1,2,4-triazol-5-yl) salicylamide)(manufactured by ADEKA) was added to 100 parts by mass of Cs_(0.33)WO₃particles so as to be 200 parts by mass.

Table 1 shows a mixing ratio of the dark powder dispersion liquidaccording to examples 1 to 12 and comparative examples 1 to 8.

An ultraviolet curing resin (Aronix UV3701 manufactured by Toagosei Co.,Ltd.) was mixed with each of the dark powder dispersion liquidsaccording to examples 1 to 12 and comparative examples 1 to 8, toprepare a dispersion liquid (coating liquid) for forming a dark powderdispersion body according to examples 1 to 12 and comparative examples 1to 8.

Here, in the dispersion liquid (coating liquid) for forming a darkpowder dispersion body according to examples 1 to 12 and comparativeexamples 1 to 8, the dark powder dispersion liquid and UV curable resinwere mixed, aiming for the visible light transmittance of the darkpowder dispersion liquid after curing described later to be 40% inexample 1, 35% in example 2, 30% in example 3, 65% in example 4, 50% inexample 5, 35% in example 6, 20% in example 7, 65% in example 8, 55% inexample 9, 65% in example 10, 65% in example 11, 65% in example 12, 15%in comparative example 1, 30% in comparative example 2, 40% incomparative example 3, 50% in comparative example 4, 65% in comparativeexample 5, 40% in comparative example 6, 30% in comparative example 7,and 20% in comparative example 8.

(d) Preparation of Dark Powder Dispersion Body and ColoredLayer-Attached Base Material

A PET film having a thickness of 50 μm was coated with each of thedispersion liquids (coating liquids) for forming a dark powderdispersion body according to examples 1 to 12 and comparative examples 1to 8, with No. 4 to No. 10 bar coaters to obtain a coating film. Afterevaporating the solvent from the obtained coating film to be dried(heating at 70° C. for 1 minute), the coating film gas cured underirradiation of ultraviolet rays using a high-pressure mercury lamp toprovide a dark powder dispersion body on the surface of the PET film.The provided dark powder dispersion body is a colored layer, and thecolored layer was formed on the surface of the PET film and used as asample film. This means that the colored layer-attached base materialsaccording to examples 1 to 12 and comparative examples 1 to 8 wereprepared.

As for the colored layer-attached base materials prepared according toexamples 1 to 12 and comparative examples 1 to 8, the chroma c*, visiblelight transmittance, and near-infrared transmittance were measured.Table 1 shows the results. In the measurement of the chroma, visiblelight transmittance, and near infrared transmittance, values includingthe PET film as a base material were measured.

(e) Evaluation of Humidity and Heat Resistance of the ColoredLayer-Attached Base Material

As for the colored layer-attached base materials (sample films)according to examples 8 and 10 to 12, a change in a transmissionspectrum was measured in an environment of a temperature of 85° C. and arelative humidity of 90%, and thereafter, a change in absorbance overtime at a wavelength of 1000 nm calculated from the transmissionspectrum was evaluated.

Evaluation of the colored layer-attached base material sample (samplefilm) was performed in the following procedure.

First, a transmission spectrum of the prepared sample film was measuredin a wavelength range of 200 nm to 2600 nm to obtain a transmittance ata wavelength of 1000 nm. Thereafter, the sample film was placed in aconstant temperature and humidity chamber with a temperature of 85° C.and a relative humidity of 90%. After a predetermined number of dayspassed after the sample film was placed in, the sample film was takenout, and a transmission spectrum was measured in the wavelength rangedescribed above to obtain the transmittance at a wavelength of 1000 nm.Thereafter, the sample film was placed again in the constant temperatureand humidity chamber under the above temperature and humidityconditions, and after a predetermined number of days had passed, thesample film was taken out again and the transmittance at a wavelength of1000 nm was determined repeatedly.

Then, the transmittance at the wavelength of 1000 nm was converted intoabsorbance using the following formula 3, and a rate of change inabsorbance from the start of a test was determined.

Table 2 shows a rate of change in absorbance of the sample film after apredetermined number of days from the start of the test, and FIG. 1shows a rate of change in absorbance of the sample film after apredetermined number of days from the start of the test, as for thecolored layer-attached base material according to examples 8 and 10 to12.

In FIG. 1 , a vertical axis is the rate of change in absorbance at awavelength of 1000 nm, and a horizontal axis is elapsed days.

Then, data of the sample film of example 8 is indicated by a shortdashed line, data of the sample film of example 10 is indicated by asolid line, data of the sample film of example 11 is indicated by adashed line, and data of the sample film of example 12 is indicated by along broken line.

Absorbance=−log (transmittance)   Formula 3

(f) Conclusion

When comparing example 1, comparative example 3, and comparative example6, which are formulations aimed at a visible light transmittance of 40%,measured values of the visible light transmittance are all about 40%. Onthe other hand, the chroma c* was found to be low in example 1.

Similarly, when comparing example 3, comparative example 2, andcomparative example 7, which are formulations aimed at a visible lighttransmittance of 30%, measured values of the visible light transmittanceare all about 30%. On the other hand, the chroma c* was found to be lowin example 3.

Similarly, when comparing example 7 and comparative example 8, which areformulations aimed at a visible light transmittance of 20%, measuredvalues of the visible light transmittance are all about 20%. On theother hand, the chroma c* was found to be low in example 7.

Similarly, when comparing example 4 and comparative example 5, which areformulations aimed at a visible light transmittance of 65%, measuredvalues of the visible light transmittance are all about 65%. On theother hand, the chroma c* was found to be low in example 4.

Then, the visible light transmittance and the near-infraredtransmittance could be desired values while maintaining the value of c*at 4.5 or less, by selecting the Cu—Fe—Mn composite oxide pigment or theCu—Cr composite oxide pigment as a dark pigment, and by changing amixing ratio in the dark powder dispersion body that is a mixture of thedark pigment, the composite tungsten oxide fine particles and a mediumsuch as a resin

Next, the following was found from FIG. 1 showing the results of theevaluation of humidity and heat resistance, in which the coloredlayer-attached base materials according to examples 8 and 10 to 12 areused.

When comparing example 8 and example 10, it was found that the rate ofchange in absorbance over time is smaller in example 10. It is estimatedthat this is because metal ions in the colored layer-attached basematerial are captured by carbonate ions in the additive carbonate,thereby suppressing deterioration of the Cs_(0.33)WO₃ particles.

Similarly, when example 8 and example 11 were compared, it was foundthat the rate of change in absorbance over time is smaller in example11. It is estimated that this is because metal ions in the coloredlayer-attached base material are captured by lactate ions in theadditive magnesium lactate, thereby suppressing deterioration of theCs_(0.33)WO₃ particles.

Similarly, when comparing example 8 and example 12, it was found thatthe rate of change in absorbance over time is smaller in example 12. Itis estimated that this is because metal ions in the coloredlayer-attached base material are captured by additive salicylic acidderivative, thereby suppressing deterioration of the Cs_(0.33)WO₃particles.

From the evaluation of the humidity and heat resistance in which thecolored layer-attached base materials according to examples 8 and 10 to12 are used, it was found that by adding a metal deactivator or a metalsalt to a film in which the dark powder dispersion liquid is used, therate of change in absorbance after 15 days (360 hours) at a wavelengthof 1000 nm can be suppressed by 30% to 50% compared to a film in whichan additive-free dark powder dispersion liquid is used.

As described above, it was found that by adding the salicylic acidderivative or the metal salt to the dark powder dispersion body which isa mixture of the Cu—Fe—Mn composite oxide pigment as a dark pigment, thecomposite tungsten oxide fine particles, and the medium resin, etc., itis possible to suppress the change in absorbance of the dark powderdispersion body, that is, to improve the humidity and heat resistance.

TABLE 1 dark pigment composite tungsten oxide additive visible lightnear-infrared mixing ratio mixing ratio mixing ratio transmittancetransmittance kind (part by mass) kind (part by mass) kind (part bymass) c* (%) (%) Example 1 Cu—Fe—Mn 100 Cs_(0.33)WO₃ 100 — — 2.3 40.542.4 Example 2 Cu—Fe—Mn 100 Cs_(0.33)WO₃ 100 — — 3.4 35.4 38.4 Example 3Cu—Fe—Mn 100 Cs_(0.33)WO₃ 100 — — 2.7 29.4 31.2 Example 4 Cu—Fe—Mn 20Cs_(0.33)WO₃ 100 — — 1.6 64.7 38.9 Example 5 Cu—Fe—Mn 20 Cs_(0.33)WO₃100 — — 2.6 49.8 19.8 Example 6 Cu—Fe—Mn 20 Cs_(0.33)WO₃ 100 — — 3.435.9 9.3 Example 7 Cu—Fe—Mn 20 Cs_(0.33)WO₃ 100 — — 4.4 21.1 2.7 Example8 Cu—Fe—Mn 10 Cs_(0.33)WO₃ 100 — — 2.9 63.8 21.7 Example 9 Cu—Cr 20Cs_(0.33)WO₃ 100 — — 3.9 55.4 21.0 Example 10 Cu—Fe—Mn 10 Cs_(0.33)WO₃100 A 800 2.4 64.2 27.4 Example 11 Cu—Fe—Mn 10 Cs_(0.33)WO₃ 100 B 8002.1 68.1 35.0 Example 12 Cu—Fe—Mn 10 Cs_(0.33)WO₃ 100 C 200 4.2 63.213.7 Com.ex. 1 — — Cs_(0.33)WO₃ 100 — — 24.4 14.4 0.0 Com.ex. 2 — —Cs_(0.33)WO₃ 100 — — 21.6 27.0 0.0 Com.ex. 3 — — Cs_(0.33)WO₃ 100 — —18.7 37.1 0.1 Com.ex. 4 — — Cs_(0.33)WO₃ 100 — — 14.4 51.4 0.4 Com.ex. 5— — Cs_(0.33)WO₃ 100 — — 11.0 62.6 1.6 Com.ex. 6 Cu—Fe—Mn 100 — — — —4.4 40.0 58.5 Com.ex. 7 Cu—Fe—Mn 100 — — — — 5.1 31.0 64.8 Com.ex. 8Cu—Fe—Mn 100 — — — — 6.1 19.7 70.2 Com.ex. = Comparative example A = Mgcarbonate hydroxide B = Mg lactate C = Salicylic acid derivative

TABLE 2 Elapsed days from start of test (days) 1 2 3 5 7 8 12 15 16 17Example 8 — −0.13 — −0.20 — −0.23 −0.27 — — — Example 10 −0.09 — −0.12 —−0.14 — — — −0.138 — Example 11 −0.01 — −0.05 — −0.07 — — — — −0.166Example 12 −0.06 — −0.08 — −0.13 — — −0.201 — —

1. A dark powder dispersion liquid, comprising: a dark pigment;composite tungsten oxide particles; and a solvent, wherein a mass ratioof the dark pigment to the composite tungsten oxide particles (mass ofdark pigment/mass of composite tungsten oxide fine particles) is 0.01 ormore and 5 or less.
 2. The dark powder dispersion liquid according toclaim 1, wherein the composite tungsten oxide fine particles include ahexagonal crystal structure.
 3. The dark powder dispersion liquidaccording to claim 1, wherein the dark pigment is particles having anaverage dispersed particle size of 200 nm or less.
 4. The dark powderdispersion liquid according to claim 1, wherein the pigment is one ormore kinds selected from Cu—Fe—Mn composite oxide pigment, Cu—Crcomposite oxide pigment, Cu—Cr—Mn composite oxide pigment, Cu—Cr—Mn—Nicomposite oxide pigment, Cu—Cr—Fe composite oxide pigment, Fe—Crcomposite oxide pigment and Co—Cr—Fe composite oxide pigment, titaniumblack, titanium nitride, titanium oxynitride, dark azo pigment, peryleneblack pigment, aniline black pigment, and carbon black.
 5. The darkpowder dispersion liquid according to claim 1, wherein the dark powderdispersion liquid includes one or more selected from metal deactivatorsand metal salts.
 6. The dark powder dispersion liquid according to claim1, wherein the solvent is selected from water, organic solvents, fats,liquid resins, liquid plasticizers for plastics, or a mixture of them.7. A dark powder dispersion body, comprising: a dark pigment; compositetungsten oxide particles; and a solid medium, wherein a mass ratio ofthe dark pigment to the composite tungsten oxide particles (mass of darkpigment/mass of composite tungsten oxide fine particles) is 0.01 or moreand 5 or less.
 8. The dark powder dispersion body according to claim 7,wherein the composite tungsten oxide particles include a hexagonalcrystal structure.
 9. The dark powder dispersion body according to claim7, wherein the dark pigment is particles having an average dispersedparticle size of 200 nm or less.
 10. The dark powder dispersion bodyaccording to claim 7, wherein the pigment is one or more kinds selectedfrom Cu—Fe—Mn composite oxide pigment, Cu—Cr composite oxide pigment,Cu—Cr—Mn composite oxide pigment, Cu—Cr—Mn—Ni composite oxide pigment,Cu—Cr—Fe composite oxide pigment, Fe—Cr composite oxide pigment andCo—Cr—Fe composite oxide pigment, titanium black, titanium nitride,titanium oxynitride, dark azo pigment, perylene black pigment, anilineblack pigment, and carbon black.
 11. The dark powder dispersion bodyaccording to claim 7, wherein the dispersion body comprises one or moreselected from metal deactivators or metal salts.
 12. The dark powderdispersion body according to claim 7, wherein the solid medium is aresin.
 13. A colored layer-attached base material, wherein a coloredlayer is provided on at least one surface of a transparent basematerial, and the colored layer is the dark powder dispersion body ofclaim
 7. 14. The colored layer-attached base material according to claim13, wherein the transparent base material is a transparent film basematerial or a transparent glass base material.